Welcome to the AC Tropical Fish aquarium forum. Our aquarium forum is the place to discuss any aquarium related issue in a friendly environment. Our aquarium forum welcomes aquarists of all levels from beginners to experts. Please ask a question in the how to section of our forum or read the FAQ section if you have any questions. register to and become a part of our friendly aquarium forum community today.

Neon Tetra Disease? Columnaris? Any takers?

This isn't the first time I've tried diagnosing or asked someone to help diagnosing this "disease" my fish have been getting, but I figured I'd give it another shot with some additional photos.

Here's the lowdown: The only fish that come down with this disease are my Black Phantom Tetras. I started out with 10 of them and they've been dying off one by one over the course of a few months. None of my other fish have been dying of disease, nor have any showed symptoms of the same disease.

When one of my poor little fish comes down with this stuff, the first symptom seems to be two symmetrically raised dots at the base of their tail fin, on either side.

They can last for a while like this and show no other symptoms. Then, all of a sudden (maybe a week or two later) they'll start to show signs of lethargy. They stop swimming with the other fish, they take cover either under or behind plants and hover in the same place for the remainder of their days, unless another fish gets antsy around them.

They also lose their appetite at this time. They won't touch food... not even if it drops right in front of them.

In one case, the fish was showing signs of Swim Bladder Disease, in that she couldn't keep her tail level with the rest of her body.

This is also when they start breathing more erratically and begin gasping for air.

In a few instances, there has been decay around the mouth. In two instances, fish have lost either the top part of their tail fin or the entire tail fin.

This time, the Black Phantom has a raised bump on her dorsal fin and has a white spot under her mouth (so I expect her mouth to decay like the others).

This is a better visual of the dorsal fin, but nothing else. It really brings out the bump at the base.

This is a better visual of the growth under her mouth.

I've tried treating the entire tank with salt, QTing and treating with salt, QTing and treating with Fungus Guard, QTing and treating with Coppersafe. Nothing has worked and in most cases, the stress of being moved from the main tank to the QT has killed them within a day. If left to their own devices in the main tank, they can last quite a bit longer. That being said, it will have reached the point where they're probably suffering.

It's gotten to that point, where once they start showing signs of gasping for air, and since nothing else has worked, I've decided to put them down using the freezing method.

I posted more pictures this time, in hopes that someone can figure this out. No one could, last time, and I would hope that we could nip this in the bud. Maybe it's poor breeding... and a mutation occurred as a result. I don't know... but I do know it's not happening to any of my other fish.

Let me know what you think - I'm at a loss.

Edit: Not sure if this is a symptom or not... but I've noticed through the pictures, that her gills seem to be flaring - probably because of the trouble breathing. It makes her gills look really red.